Earlier this month, the ACS released its annual report on Cancer Facts and Figures. The document, based largely on analyses of SEER data from the NCI, supports that approximately 229,000 adults in the U.S. will receive a diagnosis of invasive breast cancer (BC) this year. The disease affects just over 2,000 men annually; 99% of cases arise in women. Non-invasive, aka in situ or Stage 0 BC, including DCIS, will be found in approximately 63,000 individuals.

The slightly encouraging news is that BC mortality continues to decline. This year, the number of expected deaths from BC is just under 40,000. From the ACS document: “Steady declines in breast cancer mortality among women since 1990 have been attributed to a combination of early detection and improvements in treatment.”

Survival data, from the report:

For all women diagnosed with BC, the 5-year relative survival rate has risen from 63% in the 1960s to 90% today. At 10 years, for women of all stages combined, the relative survival is 82% and at 15 years, 77%. Traditional staging still matters: For women with localized BC (that has not spread to glands or elsewhere outside of the breast), the 5-year relative survival at 5 years is 99%. For women with lymph node involvement, 5-year relative survival is 84%.

For those with metastatic disease, 5-year relative survival is 23%. The report cautions: these “stats don’t reflect recent advances in detection and treatment. For example, 15-year relative survival is based on patients diagnosed as early as 1990.”

Since 1990, we’ve seen testing and widespread use of (no longer) new drugs like Herceptin, taxane-type chemotherapies, aromatase inhibitors and other meds in women with MBC. In addition, it’s possible that better palliative care and supportive strategies, along with more effective treatments for infectious and other complications, may have extended survival.

What we’ve got to ask, and about which data are remarkably elusive, is this: What is the median survival for women with metastatic BC (MBC) in 2012?

Your author has spoken with several leading, national authorities on the subject, and no one has provided a clear answer. The reason for this informational hole is that SEER data includes the incidence of new cases at each stage, and mortality from the disease, but does not include numbers on stage conversion – when a woman who had early-stage disease relapses with Stage IV (MBC). There’s astonishingly little current data about on how long women live, on average, after relapsing.

20 years ago, oncology fellows learned that the median survival of women with MBC was around 3 years. Now, that is pretty much still what doctors tell patients, but there’s a sense that the picture is no longer so bleak. Much of what we know about survival of women with MBC comes from clinical trials of patients with particular subtypes (e.g. Her2+ or negative disease). That information, on subtypes and responsiveness to particular drugs, is crucial. But we also need to know the big picture, i.e. exactly – give or take a few thousand women – how many are alive now with MBC?

This information might inform research funding, planning of medical and social services, besides understanding the course of the illness and extensiveness of this problem. And if survival has indeed improved, that measurement, straightforward as it should be, might offer hope to those living with the disease, today.